How To Frame A Hip Roof - Including A Common Rafter Review

Summary

This instructional video teaches viewers how to frame a hip roof using a framing square and a calculator. It covers the process of calculating and installing common rafters, as well as the layout and cutting of hip and jack rafters. The video provides a quick method for calculating common rafters using the run and pitch, and demonstrates how to use a framing square for precise cuts. It also explains the adjustments needed for hip rafters due to their 45-degree angle and how to calculate jack rafter lengths, ensuring a snug fit for all roof components.

Takeaways

• 🏠 Framing a hip roof involves using common rafters, hip rafters, and jack rafters.
• 📏 A framing square and a calculator are essential tools for calculating and laying out the roof components.
• 📐 The 'run' is calculated as half the total span minus half the thickness of the ridge material.
• 📈 The 'pitch' is the roof's rise per 12 inches of run, determined by personal preference or design specifications.
• 🔢 For common rafters, use the construction calculator to input the run and pitch to find the diagonal measurement.
• 📝 Layout for common rafters includes marking for the birdsmouth, soffit, and fascia cuts using a framing square.
• 👑 The 'king common rafter' is the first common rafter installed, which aligns with the ridge and center line on the plate.
• 🔄 The hip roof starts a specific distance back from the building's edge, which is the run measurement.
• 🛠️ Hip rafters have a different run measurement (17 inches instead of 12) due to their angle to the ridge board.
• ✂️ Jack rafters are shorter and have a 45-degree bevel at the top, with a common rafter seat cut and tail assembly.
• 🏁 The process requires careful measurement and cutting, with adjustments for overhangs and the thickness of materials.

Q & A

What are the main components of a hip roof?

A hip roof is composed of common rafters, hip rafters, and jack rafters.

What is the purpose of calculating the common rafters before framing a hip roof?

Calculating and installing common rafters is essential as they form the base structure of the hip roof, and the hip rafters and jack rafters are positioned relative to them.

What two measurements are required to calculate common rafters using a construction calculator?

The two measurements needed are the run and the pitch. The run is half the distance of the total span minus half the thickness of the ridge material, while the pitch is the roof's rise per 12 inches of run.

How is the run calculated for the common rafters?

The run is calculated as half the total span of the roof minus half the thickness of the ridge material.

What does the pitch represent in the context of framing a hip roof?

The pitch represents how much the roof rises per 12 inches of horizontal run, which is dependent on personal preference, codes, or designer specifications.

How do you use a framing square to layout a common rafter?

To layout a common rafter with a framing square, align the pitch mark on the tongue side with the edge of the wood, then align the 12-inch mark on the other side, clamp it in place, and trace the tongue angle at the top of the rafter.

What is the purpose of the birdsmouth cut in the rafter?

The birdsmouth cut in the rafter is designed to allow the rafter to sit on the top plate of the wall and provide support for the roof sheathing.

How do you determine the starting point for the hip roof?

The hip roof starts 23 and a quarter inches back from the edge of the building, which corresponds to the run measurement.

What is the difference between a common rafter and a hip rafter?

A common rafter runs from the wall plate to the ridge, while a hip rafter extends from the corner of the building up to the ridge, forming the corner edge of the roof.

How do you calculate the length of a hip rafter using a calculator?

After inputting the common rafter length into the calculator, you press the hip and valley button to find the total length of the hip rafter, which does not include the overhang.

Why is the run measurement of the framing square adjusted when laying out hip rafters?

The run measurement is adjusted from 12 inches to 17 inches to account for the slower rise of the hip rafter compared to the common rafter, ensuring the correct angle and fit for the hip rafter.

Outlines

00:00

🏠 Framing a Hip Roof: Introduction and Common Rafter Calculation

This paragraph introduces the process of framing a hip roof, focusing on the use of a framing square and a calculator. It explains the components of a hip roof, including common rafters, hip rafters, and jack rafters. The presenter provides a quick overview of calculating common rafters, emphasizing the need for the run and pitch measurements. The run is calculated as half the total span minus half the thickness of the ridge material. The pitch is the roof's rise per 12 inches of run, which is determined by personal preference or design specifications. The presenter demonstrates how to use a construction calculator to find the diagonal measurement of the rafters, which is 26 inches in the example. The paragraph concludes with a demonstration of how to use a framing square to layout and cut a common rafter, including marking for the birdsmouth, soffit, and fascia cuts.

05:01

🛠️ Hip Rafter and Jack Rafter Calculations

In this paragraph, the focus shifts to calculating and laying out hip rafters. The presenter explains that hip rafters have a different run measurement due to their 45-degree angle to the ridge board, requiring an adjustment from 12 inches to 17 inches on the framing square. It's noted that hip rafters and ridge boards are typically one size larger than the common rafters. The presenter demonstrates how to mark and cut the hip rafters, including the double bevel cut at the top and the seat cut, which is based on the height above the plate rather than the wall thickness. The paragraph also covers the calculation and layout for jack rafters, highlighting the need to adjust the length of jack rafters to account for the thickness of the hip material. The presenter provides a step-by-step guide on how to use the framing square to mark the top cut, seat cut, and overhang for jack rafters, and how to create mirrored copies for rafters on the opposite side of the hip.

10:02

🔨 Finalizing the Roof Framing Process

The final paragraph wraps up the video by discussing the installation of the hip and jack rafters. It emphasizes the importance of checking the fit of the hip rafters and ensuring they align properly with the exterior walls and other king rafters. The presenter advises using the correctly cut hip rafter as a pattern for cutting the remaining hips. The paragraph also addresses the need to adjust the length of jack rafters to ensure they are spaced 16 inches on center, accounting for the thickness of the hip material. The presenter provides a detailed walkthrough of laying out and cutting jack rafters, including the top angle, seat cut, and tail assembly. The video concludes with a reminder to consult local building codes and an invitation for viewers to ask questions or reach out via social media.

Keywords

💡Hip Roof

A hip roof is a type of roof where all sides slope downwards to the walls, and all sides have the same slope. It's a common architectural feature that provides a distinctive look and can offer practical benefits such as shedding snow and rain effectively. In the video, the host is teaching how to frame a hip roof, which involves understanding its components like common rafters, hip rafters, and jack rafters.

💡Framing Square

A framing square is a tool used in carpentry to lay out and cut rafters, studs, and other framing members at the correct angles. It's essential for constructing roofs and walls accurately. In the video, the framing square is used to set up the angles for cutting common rafters, hip rafters, and jack rafters, demonstrating its critical role in the framing process.

💡Common Rafters

Common rafters are the sloping structural members that support the roof sheathing and are perpendicular to the ridge. They are a fundamental part of a roof's framing. The video script explains how to calculate and lay out common rafters using the framing square and a calculator, emphasizing their importance in the framing of a hip roof.

💡Hip Rafters

Hip rafters are the rafters that form the intersection of the roof with the wall, transitioning from the sloping roof to the vertical wall. They are a distinctive feature of hip roofs. The video provides a detailed explanation of how to calculate the length of hip rafters and how to lay them out using the framing square, highlighting their unique role in the construction of a hip roof.

💡Jack Rafters

Jack rafters are short rafters that are used at the lower end of a gable or hip roof, where the roof meets the wall. They are crucial for supporting the eaves and providing a finished look to the roof's edge. The video script includes instructions on how to calculate and cut jack rafters, showing their importance in completing the roof's structure.

💡Run

In the context of roofing, the run is the horizontal distance from the ridge to the eave of a roof, typically measured in inches. It's a key measurement used in calculating the length and slope of rafters. The video script explains how to determine the run by using the total span and the thickness of the ridge material, which is essential for framing a hip roof.

💡Pitch

Pitch refers to the steepness or slope of a roof, measured as the rise over a given horizontal distance, often 12 inches. It's a critical factor in roof design and construction. The video script demonstrates how to use pitch in conjunction with the run to calculate the diagonal measurement of rafters using a construction calculator.

💡Birdsmouth

A birdsmouth is a cut made in the rafter to allow it to fit snugly against the wall and support the roof sheathing. It's an important detail in roof framing that ensures stability and a proper fit. The video script describes how to lay out and cut the birdsmouth as part of the common rafter, showcasing its role in the overall roof framing process.

💡Overhang

Overhang in roofing refers to the part of the roof that extends beyond the exterior walls of a building. It's a design element that can provide additional protection from the elements and aesthetic appeal. The video script includes instructions on how to calculate and mark the overhang for both common and hip rafters, emphasizing its importance in the overall roof design.

💡Soffit Cut

The soffit cut is the angled cut made at the bottom of a rafter to allow it to fit against the wall and support the soffit, which is the underside of the eaves. It's a critical part of the rafter's layout and ensures a clean finish for the roof's underside. The video script describes how to make the soffit cut for both common and hip rafters, illustrating its role in the roof's appearance and function.

💡Construction Calculator

A construction calculator is a specialized tool or device used to perform calculations related to construction projects, such as roof framing. It can simplify complex mathematical problems and provide quick, accurate results. The video script mentions using a construction calculator to determine the lengths and angles of various roof components, highlighting its utility in the framing process.

Highlights

Introduction to framing a hip roof using a framing square and a calculator.

Explanation of the components of a hip roof: common rafters, hip rafters, and jack rafters.

Prerequisite of having calculated and installed common rafters before framing a hip roof.

Quick overview of calculating common rafters using a construction calculator with run and pitch.

Demonstration of a faster way to calculate common rafters.

Detailed calculation of run and pitch for a mock-up with a total span of four feet.

Instructions on using a framing square attached to wood for accurate layout.

Process of setting up the framing square for a common rafter and marking the tongue angle.

Laying out and cutting for the birdsmouth, soffit, and fascia cut on a common rafter.

Transformation of a common rafter into a king common rafter in a hip roof.

Determining the starting point of the hip roof from the edge of the building.

Calculating the length of hip rafters using the calculator's hip and valley button.

Adjusting the framing square's run to account for the slower rise of hip rafters.

Marking the top cut of hip rafters and preparing for the double bevel cut.

Explanation of the rafter drop and how to calculate it for hip rafters.

Laying out the overhang amount for hip rafters using pitch and run calculations.

Cutting the soffit cut for hip rafters by extending the seat cut line.

Using the cut hip rafter as a pattern to cut and install remaining hips.

Laying out and cutting jack rafters, including adjustments for hip thickness.

Final reminder to check local building codes for proper framing techniques and sizing.

Transcripts

- Today, we're learning how to frame a hip roof

using a framing square and a calculator.

Hip roofs like our mock-up here today

are made up of common rafters, hip rafters,

and jack rafters.

In order to frame a hip roof,

you must have already calculated

and installed your common rafters.

Now because I've already done two videos

on how to lay out and cut common rafters,

which I'll link below,

I'm not gonna get into too much detail in this video.

However, I will give you a quick overview

demonstrating yet a faster way to calculate common rafters.

When using a construction calculator

to solve for common rafters, you only need two numbers,

the run and the pitch.

The run is half the distance of the total span

minus half the thickness of the ridge material.

For example, this mock-up has a total span of four feet,

which is measured from its outside edges.

So half of that is 24 inches.

The ridge is an inch and a half wide.

So half of that would be three-quarters of an inch.

Therefore, 24 minus three-quarters

leaves us with a run of 23 and a quarter.

Pitch is how much the roof rises per 12 inches of run.

For example, for every 12 inches of horizontal run,

our roof rises six inches.

This number is completely dependent on personal preference,

codes, or specified by a designer.

On the calculator, type 23 and one-quarter inch

and press the run button.

Then type six inches, and then the pitch button

followed by the diagonal button

for a measurement of 26 inches.

26 inches is the rafters diagonal measurement

which is from this tip here down to the black line.

And it does not include the overhang.

So, let's go over and do some layout to figure this all out.

The majority of our layout will be done today

using the framing square,

that's actually attached to a piece of wood

with some simple clamps.

What this will do is allow the square to move freely

and accurately over the lumber.

To set up for a common rafter,

line up the six mark on the tongue side

with the edge of your wood.

This represents the pitch or rise.

Then line up the 12 inch mark with the other side

and clamp it in place.

Again, this represents our run.

Now slide to square up to the top of the rafter,

trace the tongue angle, and cut the angle with a saw.

From there, measure down from the top of the rafter,

26 inches, make a mark and draw a second line.

So far, we've laid out this part right here.

And now we need to lay out

and cut for the birdsmouth, the soffit, and the fascia cut.

The seat cut for the birdsmouth

is to the right of this line.

And it's four inches long for this mock-up.

So line up the four and draw a line.

And that gets cut out.

Next is the overhang, which is five inches from this line.

So line the tongue back up, measure over five,

make a mark, and draw another line.

The last line to mark is the soffit cut,

which forms the four-inch fascia.

Measure down four inches, make a mark,

and then draw a line.

And this all gets cut out.

Once everything is cut out,

you now have a finished common rafter.

Because we're focusing mainly on building a hip roof today,

we're actually gonna use this common rafter

that we just cut to start forming today's hip roof.

Once installed here, there common rafter

becomes known as the king common rafter or just king rafter.

And it gets lined up with the ridge at the top

and on the center line down on the plate.

And you may be wondering,

how do you know where the common roof ends

and the hip roof starts?

Well, it's actually pretty simple.

The hip roof starts 23 and quarter inches

back from the edge of the building,

which is exactly our run.

Moving on, let's start working on the hip rafters,

which go from the bottom corner here

all the way up to the ridge.

If we look back at our calculator,

you can see that it's still showing our common rafter length

of 26 inches.

From there, all you have to do

to find the length of the hip rafter

is to push the hip and valley button

for a total length of 34 and seven-eighths.

Again, this measurement does not include the overhang.

So we'll need to add that

just like we did for the common rafter.

There's one more number that we need to figure out

before we clear the calculator out,

and that is the jack rafter lengths.

Still on the screen is 34 and seven-eighths.

And all we have to do to find the first jack

is to hit the jack button until you see jack number one,

which for us is eight and an eighth.

If you hit the button another time,

you can see the jack two is zero inches.

And it's zero because our roof is so small

that there's no other jacks needed.

If you had a larger roof,

you would just continue to hit the button

and cycle through all the jack rafters needed for your roof.

Because hip rafters are at a 45 degree angle

to the ridge board, they rise slower

or more gradually than the common rafter would.

Therefore, we need to account for this

by changing the run of our square from 12 inches

to 17 inches.

Just make sure that when you make that adjustment,

double check that the tongue measurement of six inches

is still right on.

The other thing to note before we begin layout

is that hip rafters along with ridge boards

are generally one size larger than the rafters themselves.

So for our example back here,

we're using two by six rafters.

So the ridge and the hips are two by eights.

All right, with the framing square set to six and 17,

mark out the top cut by drawing a line.

And this time adding two more lines

three-quarters of an inch to the right and to the left.

We will use these additional lines

as guides to make our double bevel cut

at the top of the rafter.

If we look back at the two rafters in our mock-up,

you will see that the hip rafter

has to be pointed in order to fit tightly into that space.

With the saw beveled to 45 degrees,

cut the right line first, which is the waste side,

and then cut the other side.

When you're done, your cut should look like this.

From there, take your tape measure

and hook it over the point

and measure down the rafter length,

which is 34 and seven-eighths.

Make a mark and draw another line.

On common rafters, the seat cut which is this part here,

is generally the same thickness of the exterior wall.

In this case, it's four inches.

However, we can't use that same seat cut measurement

for our hip rafters.

But what we can use is the height above plate.

Height above plate is this measurement right here.

It's a straight line

that goes right up to the edge of the rafter.

And in our case, it's four and a 16th.

If we now go back to our layout,

we can measure down four and a 16th,

make a mark, and draw the seat cut.

Now we're not quite done with the seat cut yet.

Because if we were to cut that line right here,

the rafter would fit, but it would be too high.

Again, because the rafter is coming in at a 45 degree angle,

it needs to sit down or be dropped

so that the rafter edges meet like this.

The amount of rafter drop

is based on half the thickness of the hip material.

So in this case, it's three-quarters of an inch.

Back at the layout,

measure to the right of this line three-quarters of an inch,

and make a short mark.

Then remeasure down our four and one-16th,

which is our height above plate, and make another mark.

The distance between these two lines

is the amount of rafter drop needed for this roof.

All you have to do then is slide the square

up to that new line and draw a new seat cut.

Next up is the overhang amount.

Because this is a hip rafter,

we can't simply measure out five

like we did with a common rafter.

Rather, we need to figure out

how far down the slope we need to go

in order to locate the correct amount of overhang.

I know that's a little confusing.

So let me draw a picture.

What we're trying to figure out

is how far down the slope we need to go

to get the correct amount of overhang.

So we don't know this number.

However, we do know the other two numbers in this equation

and that is the overhang amount of the common rafter,

which is five inches,

and the pitch of our roof is six inches.

Therefore, on the calculator type five inch run,

six inch pitch.

And because this is a hip rafter and not a common rafter,

we're gonna hit the hip and valley button

for a total of seven and a half inches.

If we go back to our layout,

we can measure down now seven and a half inches,

make a mark, and draw our overhang.

Again, because this is a hip rafter,

this cut needs to have a double bevel cut

just like at the top.

So like before,

we're gonna measure three-quarters of an inch on either side

and draw two lines.

Remember, once both lines are cut at a 45 degree bevel,

the center line will end up being the tip

of those two bevels.

The last thing to lay out would be the soffit cut.

And in order to do that,

we need to first extend our seat cut line

over to meet the overhang or fascia cut line.

And now, it's back to the common rafter

to measure the distance between the seat cut

and the soffit, which is two and five-eighths.

Transfer that measurement

down from our extended seat cut line,

make a mark, and draw the soffit cut line.

Again, there's a lot of lines here,

so let me darken them so you can see more clearly.

First we're cutting the fascia, the heel cut,

and the seat cut, which makes up the birdsmouth.

And then we're cutting the soffit.

But remember that the center fascia line

is cut using two 45 degree bevels.

Cutting the waste side first and then the other side.

Be careful to position (indistinct) material safely

as you work through making each cut.

With the hip now cut,

it's a good idea to lay out the 45 degree angle

for the rafters.

So, you know exactly where it fits.

Once installed,

double check it's fitting tight to the exterior.

And the top corners of the hip

are lined up with the other king rafters.

Because this hip fits,

use it as a pattern to cut out the remaining hip

and install it.

The last thing to do is lay out and cut our jack rafters.

Because this roof is laid out 16 inches on center,

let's pull a tape from the left side of this king rafter,

measure our 16 inches, draw a line,

and mark an X where the rafter gets installed.

Because this roof is so small,

it only needs one jack rafter.

And if you remember the length of that rafter

is eight and an eighth.

Now there's one thing to note

about the Construction Pro Calculator

and that it doesn't take into account

the thickness of the hip when calculating the jack rafters.

Therefore, because our hip is an inch and a half thick,

we have to add seven-16th

to the overall length of the jack rafters

in order to get them to land exactly 16 on center.

So all we have to do is simply add seven-16ths

to our eight and eighth to get a total jack rafter length

of eight nine-16ths.

To lay out the jack rafters,

you have to put your square back to a six, 12.

Again, because we're not cutting hips anymore.

Jack rafters also have 45 degree bevels at the top

and a common rafter seat cut and tail assembly.

Therefore, you can lay these out individually if you want,

or you can make a copy of the common rafter tail

simply by tracing it out and using it as a pattern.

It starts by laying out the top angle

set to your six and 12.

Set this all at a 45 degree bevel and make your cut.

Measure down from the long point of that bevel

eight and nine-16ths and draw another line.

From there, line up your pattern,

trace it out, and make the cuts.

Now because some of the jack rafters

are on the opposite side of the hip,

you'll have to make mirrored copies

so that the 45 degree angles

are going in the right direction.

To do that,

simply lay one jack down with a long point facing down

and trace the whole jack out.

And now when you cut this new jack,

just make sure that you're cutting

with the saw beveled in the opposite direction

so that you're making a mirrored copy.

With everything cut,

install the remaining jacks to finish the roof.

As a reminder, this is just a mock-up roof.

So you need to make sure

to check with all of your local building codes

so you can find the correct ways to attach

and size all the framing members.

Now, we went over a lot of information really quickly.

So I broken down this video into chapters

so you can go back and do each step easily.

So, if you have any questions,

hit me up in the comment section below.

You can find me on Instagram.

That always works as well.

Thank you so much for watching today.

See you in the next video.

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